1. Field of the Invention
The invention relates to interoperability support using a dual beacon mechanism for wireless transmissions.
2. Brief Description of the Related Technology
A wireless network may comprise a plurality of devices of different types: simple device (SD) and advanced devices (AD), including devices having a directional antenna and devices having an omni-directional antenna. In order to set up a network with the simple devices and the advanced devices, solving an interoperability problem between the devices of different types is necessary. For example, the European Computer Manufacturers Association (ECMA) standard and Institute of Electrical and Electronics Engineers (IEEE) 802.15.3c are directed to the problem.
In the wireless network communication community, a coexistence and interoperability scheme was suggested. The suggestions included: (1) An AD is only capable of sending and receiving AD-waveform beacons, and is not able to send or receive SD-waveform beacons, (2) An SD is capable of sending and receiving SD-waveform beacons, and is also able to send AD-waveform beacons but not able to receive AD-waveform beacons, and (3) If an SD and an AD want to talk to each other, a master/slave approach is proposed in which an AD (master) reserves bandwidth for an SD (slave) by special signaling procedure.
However, the above approach has following drawbacks. (1) The SD implementation complexity is increased by requiring an SD to send out AD-waveform beacons. (2) Power consumption of an SD is increased due to the AD-waveform beacons. Some SDs can be portable devices which have strict power saving requirement. (3) It is difficult for an SD and an AD to discover each other and transmit data between each other. The master/slave mechanism proposed causes hidden terminal problem and interference problem.